Background
Emergence of pathogens and vectors in new hosts and new geographical
areas poses great threats for public and veterinary health (Jones et
al., 2008). Ticks are responsible for the spread of numerous pathogens
worldwide and species belonging to the genus Hyalomma have been
shown to have a particular epidemiologic role (Estrada-Peña, D́Amico, &
Fernández-Ruiz, 2020; Hubálek, Sedláček, Estrada-Peña, Vojtíšek, &
Rudolf, 2020). The tick species Hyalomma marginatum andHyalomma rufipes are the main vectors of Crimean-Congo
haemorrhagic fever virus (CCHFV). This is a negative-sense
single-stranded RNA virus belonging to the Nairoviridae family
(order Bunyavirales) . It can cause debilitating human disease
with no available casual treatment or vaccine and has a case fatality
rate up to 30% (Bente et al., 2013). The public health significance of
Crimean-Congo haemorrhagic fever is demonstrated by the fact that this
infection is geographically the most widespread tick-transmitted viral
disease in humans. It is found in the southern parts of Asia, the Middle
East, Europe and Africa. The emergence of the virus is mainly determined
by the distribution of Hyalomma ticks being responsible for the
spread of the disease agent (Bente et al., 2013).
Hyalomma marginatum and Hy. rufipes are two-host ticks
(Estrada-Peña, Mihalca, & Petney, 2018). The larva moults into a nymph
on the same first host, feeding on that animal at both stages of
development. For these two Hyalomma species, the first host is
very often a bird. The fact that they do not change host before becoming
a nymph greatly contributes to the successful geographical spread of
these ticks, as it allows them to travel longer distances by attaching
to the same migratory bird host. The adults moult from the engorged
nymphs dropping off the first host and actively look for the second
host, which is usually a large wild or domesticated mammal or human
(Valcárcel et al., 2020; Walker et al., 2003).
Although the yearly arrival of immature Hyalomma ticks with
migratory birds in temperate Europe has been a frequent phenomenon
(Capek et al., 2014), the emergence of its adults has only been detected
in higher numbers and wider distribution recently. Adults of Hy.
marginatum were found in Slovakia (Nosek, Kožuch, & Lysý, 1982) and
Austria (Duscher et al., 2018), Hyalomma rufipes adults were
found in Hungary (S Hornok & Horváth, 2012). The adults of both tick
species have recently been detected the Czech Republic (Hubálek et al.,
2020; Lesiczka et al., 2022; Rudolf et al., 2021) Germany
(Chitimia-Dobler et al., 2019), Sweden (Grandi et al., 2020), United
Kingdom (Hansford et al., 2019; McGinley et al., 2021) and the
Netherlands (Uiterwijk et al., 2021).
Citizen science, or community research, is a method that is gaining in
popularity and involvement in many research fields today. The basic idea
is that the data are collected or generated with the help of
non-researchers but are analysed by researchers specializing in the
given topic (Tran et al., 2021). Citizen science has many benefits, both
for the researchers who evaluate the data and for the citizens who
collect them. With the help of citizen science, for example,
professionals have access to the data they need without having to pay
for the work of hundreds of civilian researchers involved in the
project, and the travel, accommodation and education that may be
associated with it. It is also a great advantage that a project can be
carried out over a large geographical area for many years (MacPhail &
Colla, 2020). This approach has been successfully used in searching for
the emergence of Hyalomma adults in several European countries
(Grandi et al., 2020; Lesiczka et al., 2022; Uiterwijk et al., 2021).
In Hungary, we have limited published information about the occurrence
of Hyalomma ticks. An engorged nymph of Hy. marginatum has
been reported from a hedgehog (Erinaceus roumanicus ) living in a
Budapest city park (G Földvári et al., 2011) and two larvae and a nymph
were identified from robins (Erithacus rubecula ) (S Hornok et
al., 2013) sampled to the south of the capital. Three Hy. rufipesnymphs were reported from a common whitethroat (Sylvia communis )
in another study (S. Hornok et al., 2016). The presence of antibodies
against CCHFV has also been detected in Hungarian hares (Lepus
europaeus ) (Németh et al., 2013), rodents (Földes et al., 2019) and
recently also in humans (Magyar et al., 2021).
Based on these previous findings, the aim of our research was to obtain
a comprehensive, nationwide picture of the occurrence of adultHyalomma ticks in Hungary through a citizen science approach.
This kind of documentation is of great epidemiological importance
because this is the first step for the prevention of emerging pathogens
according to the DAMA (Document, Assess, Monitor, Act) protocol (Brooks
et al., 2014). Based on this, we plan to continuously document the
appearance of pathogens, their vectors and reservoirs hosts, then, after
the appropriate scientific analyses (Assess), we will be able to
identify the organisms that pose a threat to us and manage their
targeted surveillance (Monitor). Thus, it will be possible to make
adequate proposals to decision makers to take appropriate preventive
measures (Act) (Brooks, Hoberg, & Boeger, 2019).